In the present work, treating the arteries as a thin-walled and prestressed elastic tube with a stenosis and the blood as a Newtonian fluid with negligible viscosity, we have studied the amplitude modulation of nonlinear waves in such a composite system by use of the reductive perturbation method. The governing evolution equation was obtained as the variable coefficient nonlinear Schrödinger (N...

Friction Stir Welding (FSW) is considered to be the most significant development in metal joining technologies to join high strength aerospace aluminum alloys. In order to improve the reliability and quality of the products manufactured by FSW process input process parameters such as tool rotational speed, welding speed and axial force are to be optimized. This study deals with the optimization...

OBJECTIVE To introduce a new ophthalmic optical coherence tomography technology that allows unprecedented simultaneous ultra-high speed and ultra-high resolution. METHODS Using a superluminescent diode source, a clinically viable ultra-high speed, ultra-high resolution spectral domain optical coherence tomography system was developed. RESULTS In vivo images of the retina, the optic nerve he...

We report high-throughput optical coherence tomography (OCT) that offers 1,000 times higher axial scan rate than conventional OCT in the 800 nm spectral range. This is made possible by employing photonic time-stretch for chirping a pulse train and transforming it into a passive swept source. We demonstrate a record high axial scan rate of 90.9 MHz. To show the utility of our method, we also dem...

We propose a high-speed, parallel system for lens aberration measurement employing a confocal optical setup. This method uses a non-interferometric, conventional confocal axial response to determine the spherical aberration coefficient of a confocal objective. The aberration coefficients are successfully calculated from the intensity axial response by employing a neural network. It is estimated...

We demonstrate a high-speed tunable, continuous wave laser source for Fourier domain OCT. The laser source is based on a fiber coupled, semiconductor optical amplifier and a tunable ultrahigh finesse, fiber Fabry Perot filter for frequency tuning. The light source provides frequency scan rates of up to 20,000 sweeps per second over a wavelength range of >70 nm FWHM at 1330 nm, yielding an axial...

The present work is concerned with a numerical study of the performance of a conical annular centrifugal contractor through the analysis of the flow properties when the apex angle is changed for different imposed axial flows. The calculations revealed the advantage of using conical annular centrifugal contractors compared to the cylindrical annular centrifuges. The study is conducted by a compa...